Pressure compensator for duplicating machines



Nov. 28, 1944. R. A. WILLIAMS PRESSURE COMPENSAIOR FOR nurmcums mcnmnsFiled Sept. 18, 1942 4 Sheets-Sheet 1 INVENTOR.

Nov. 28, 1944. WILLIAMS 2,363,766

PRESSURE COMPENSATOR FOR DUPLICATING MACHINES 1 INVENTOR.

.Eoberi \fllon ro willz'ams au mmwfiu w aw, 7 Q1196 4- R. A. WILLIAMS2,363,755

PRESSURE COMPENSATOR FOR DUPLICATING MACHINES Filed Sept. 18, 1942 4SheetS-Sheet 5 I INVENTOR. ji oberi u lonyo Williams.

361M 561mm W5: zz/sza.

Nov. 28,1944. R, A. WILLIAMS PRESSURE COMPENSATOR FOR DUPLICATINGMACHINES Filed Sept. 18, 1942 4 Sheets-Sheet 4 INVENTOR. Faber-iafllonyo Williams yaw, 4 87/6851.

pressure control therefor.

Patented Nov. v 28, 1944 PRESSURE COMPENSATOR FOR DUPLICATING MACHINESRobert Alonzo Williams, Chicago, 111., assignor to Chicago, 111., acorpora- Ditto, Incorporated, tion of West Virginia ApplicationSeptember 18, 1942 Serial No. 458,782

9 Claims. (01. 101-132) The present invention relates to means forfeeding copy sheets and copy sheet assemblies to a duplicating machineand particularly to means for feeding copy sheets to the drum of such amachine into engagement with a hectograph duplicating pad or band on thedrum so as to take off copies from a copy ink design formed in reverseon the hectograph surface. A machine of the general type to which Irefer is disclosed in. the. patent to Marchev No. 2,150,744. In my priorapplication, Patent No. 2,315,175, there is disclosed a feeding meanswhich provides a downwardly converging paper guide chute with a stopplate that normally closes the chute in the pe- .applicationa resilientplate is provided as a part of the paper guide chute and it extendsbelow the stop plate. The resilient plate is adapted to press 3 againstthe opposite wall of the chute with a light pressure to aid inmaintaining proper alignment where a copy sheet assembly of the unitstrip type i (a multiplicity of sheets arranged in overlapped, oflsetrelation so that a portion of each sheet is exposed) is being fed to theduplicating drum.

In machines of this type, employed for system Work, copy sheetassemblies of the unit strip type are often used. These assembliesnaturally have a substantiallygreater thickness at their intermediateportions than at the sides. They are also of considerable weight andthey vary somewhat in thickness. The resilient plate above referred tois of particular advantage in connection with such assembliesinmaintaining alignment of the copy sheets of the assemblies as they areadvanced to the drum. However, in my prior application above referred tothe operation of the resilient plate is controlled directly bya rollerriding on a cam that is affixed to the drum, the roller being connectedto the plate by a lever arm that is pivoted to the adjacent side frame.The

.pressure of the plate under such "conditions is variable in response towear of the roller and in blies that are being fed to the drum. It isthe principal purpose of. the present invention to improve the mountingand operation of' the flexible plate whereby to obtain an accurate,uniform The more detailedobjectsand advantages of the invention willappear more fully from. the

' followingdescription, reference being bad to the accompanying drawingswherein a preferred. form of the invention is shown. r

ubstan- Fig. 3 is a sectional view. similar to Fig. 1 bu taken on theline 33 of Fig. 2

Fig. 4 is a. fragmentary sectional view taken on the line 4'-4 of Fig.2; i

Fig. 5 is a fragmentary sectional view the line 5-5 of Fig.2; 6 y

Fig. 6 is a fragmentary sectional view taken on theline 6- 6 of Fig.2;

Fig. 7 is a fragmentary. sectional view taken on the linel-J of Fig. l;and

Fig. 8 is a perspective view of a portion of the control machine that is.employed for the resilient plate.

Referring now to the several figures of the drawings, in whichcorresponding parts are indicatedby the same reference characters, l0and H indicate side frame members at opposite sides ofthei machine,suitably supported from the main framework l2 of the'machine whichisof'any approved type. Adrum 13 is rotatablysupported taken on on theframework by a transversely extending shaft M, such drum being. ofsegmental form with an opening atone side face portion, the drum beingprovided with means forholding a gelatin band l5 wrapped thereabout,comprising one or more supporting rollerslB and reels ll;

Between the frame members 10 and l I, a platen roller l8-is rotatably;mounted inposition by any suitable means,'such as the means shown bysaid prior Marchev Patent No. 2,150,744, by which means the roller ispressed yieldingly toward the drum so as to'have operative pressurerelationship withthe gelatin band on the drum. A table or tray I9 ismounted in front of the drum at a slightly higher level so .as tosupport a pile of copy sheets or copy sheetassemblies inconvenient'position for being fed by handto the sheet guiding andsupporting means of themachine for being carried one at a time intoimpression relationshipto the gelatin band. i

ed for supporting a paper guide 22 in oblique position, each of thebrackets being provided with a roller 23 rotatably mounted thereon inposition of the frame It).

framework as shown in Figs. 1 and 3 for limiting the counterclockwisemovement of the brackets in said figures. The paper guide 22 ispreferably of the type disclosed by my Patent No. 2,285,135,

issued June 2, 1942, and the structure accordingly will not-bedescribed'in detail. The arrangement is such that copy'sheetscan'readily and easily be placed in position by hand one at a time so asto be supported evenly and smoothly thereon ready for a sliding movementdownwardly on the guide when the support for the lower edge of the sheetis removed as hereinafter described. x

As is clearly shown in Figs. 1 to 3, inclusive, the paper guide 22normally stands in such position obliquely as to direct a copy sheetassembly downwardlythereon directly past the rear face of the platenroller I8 into engagement with a margin bar 24 of channel form supportedby arms 25 fixedly mounted on a shaft 26 'journalled between the framemembers I and II. The arms exten-d forwardly beyond the shaft 26 intoposition to engage a transversely extending bar 21 fixedly mounted inposition between the frame members In and II, said arms being providedwith cushions 28 in the form of rubber blocks. A coiled spring 29 on theshaft 26 normally holds the shaft 26 turned to the limit of its motionin clockwise direction in Fig. 3 for holding the margin bar 24yieldingly in raised position directly below the platen roller I8, asshownin Fig. 3. On its outer end, the shaft 26 is provided with an arm39 having a roller 3| rotatably mounted thereon in position to engage acam 32 carried around with the drum. When the cam 32 engages the roller3| as shown in Fig. 1, the continued rotation of the drum and cam causesthe shaft 26 to rotate in counterclockwise direction in said figure soas,

quickly to move the margin bar 24 downwardly and forwardly from theposition of the bar in said Fig. 1 to the position as shown in dottedlines in Fig. 3, the margin bar being held in this way out of contactwith the gelatin floand I5 on the drum.

For directing a copy sheet assembly into en I gagement with the marginbar 24 as shown'in Fig. 3, a guide plate 33 is provided, mounted rigidlyin position in front of the lowermost plate portion 34 into an aperture4| in the end of the lever arm 38.

The other end of the spring is secured to a pin plate is adapted toengage-the lower surface of a boss on the side frame I6 when the stopplate 36 is in raised position. There is a pin 42a on the cam arm 39against which the lever arm 38 is yieldingly held by the spring 46. Thusit is 6 possible for the lever arm 38 to swing in a counof the paperguide structure 22 in downwardly.

convergent position with respect thereto so as to direct the assemblyinto close proximity tothe rear face portion of the platen roller I8. Atits intermediate portion, the plate 33 is cut out and bent forwardly toprovide a flange 35 and so as to provide an opening in which a stopplate 36 is adapted to operate, such plate 36 being pivotally mountedbetween the side frames I0 and II by a shaft 3'! rotatably mounted infront of the plate 33, as is best shown in Fig. 3. Inthis arrangement,the lower edge portion of the plate is in the form of a bar extendingacross adjacent to the face of the platen roller "I8. A lever arm andlight spring arrangement is provided, as shown in Figs. 1 and 6, adaptednormally to hold the plate I 36 in raised position (see Fig. 3) adjacentto the lower edge of the plate of the paper guide so as to support onedge a copy sheet assembly resting on said plate 36 and said paper guideThe lever arm just referred to is indicated at 38and is keyed to theshaft 31 which in turn is journalled in the frame II). The lever arm 38lies outside A cam arm 391s journale'd on the shaft 31 just 'outside'thelever arm 38' (see Figs. 6 and '7). The lever arm 38 is connected to thecam arm 39 by a spring 40 that'is hooked 75 terclockwise direction withrespect to the cam arm 39 so that if the cam arm is released by itscambefore a sheet clears the stop plate 36 the plate will not be pressedagainst the sheet with sufficient force to damage it. The arrangement issuch with respect to the adjacent parts that an operator can quickly andeasily place a copy sheet assembly in position on the plate 36 so as tobe supported evenly and smoothly thereby ready for a downward movementalong the paper guide promptly when the plate 36 is swung downwardly outof supporting positionj Additional means is provided for assi'sting inthe control of the movement of a copy sheet assembly to the drum. Thismeans comprises a thin resilient pressure plate 46 which has its topedge fixed to a stiff angle bar 41. The angle bar 4'! is secured at itsopposite ends to two supporting arms 48 Whichare duplicates, except thatone is a right-hand and the other is a left-hand arm. These arms arefixed on the shaft 26 which in turn is journaled in the side frames I6and II. An arm 49 is fixed to the shaft 26 outside of the frame I6. Thisarm is forked as illustratedin Figs. 7 and 8, one arm 59 being laterallyoffset and extending at substantially right angles to the other arm 5|.The arm 5| has a cam lever 52 pivoted thereto by means of a bolt 53.Intermediate the bolt 53 and the branching of thearm 59, the arm 5| isprovided with a slot 54 extending transversely thereof and curved aboutthe bolt 53 as an axis. A bolt 55p-asses through the slot 54 and throughan aperture provided in the endof the lever 52 that overlaps the slot54. A nut 56 is threaded onto the bolt 55.- The bolt 55 extends asubstantial distance beyond the nut 56 and is connected by means of aspring 51 to the free end of the arm 56. This spring is under tension sothat it tends to draw the lever 52 toward the free end of the arm 59.The other end of the lever 52 carries a cam roller 58 which is adaptedto engage a cam 59 fixed to the drum I3.

The arms 48 are limited in the degree to which they can turn in responseto turning of the shaft 20 by means of the arms 49 and 52 when theroller 58 engages the cam 59. The limiting means comprises two stopbrackets 66 and 6| (see Figs. 3 to 5, inclusive) which are mounted ontheside frames I6 and II, respectively.

The brackets 60 and 6| are essentially the same so a description of oneis believed to be suflicient. Each bracket carries an adjustable stoppin 62 which is threaded into the bracket and which is provided with anenlarged head 63 carrying the bumper 64 of resilient material such asrubber, neoprene and the like that will yield slightly. A lock nut 65is'provided for holding the stop pin 62 in adjusted position. When amachine is set up for a particular type of Work it is only neces- "saryto set the stop pins to thereafter positively control the advance of theplate 46 toward the opposite guide plate 33.

The lever arms 48 are normally yieldingly rged to a position withdrawingthe plate 46 from contact with the other guide plate 33 by means of twospringsGB which are attached to the arms at one end and which areattached at" the other end to two pins 61 that areprovided on the sideframes l o and II. In order to limit the movement of the arms 48 inresponse to the pull of the springs 66' I provide on each of the arms'anadjustable stop pin 68 which will encgage a boss li provided on each ofthesideframes H! and H and supporting the oppositeends of a cross bar10. Alock nut ll is provided for looking the stops 68in position. l v

Theoperationbf the device is generally the same as that described inmyprior application butin order that the advantages of the presentinvention will be more readily apparent I will describe the operationand the effect of the improvements. In'the original adjustment of themachine, before-beginning to make copies,- the stops 62 are set toenablethe arms 48 to carry the plate 46 towardtheplate 33 sufficiently toobtain the proper pressure agains a sheet assemblythat is' beingadvanced to thedrum for duplication purposes. The stops 68 are alsoadjusted so as to provide ample clearance to permitt the copy sheetassembly to pass between the lower edges of the plates-33 and 46. Inmaking copies the operator initially places a copy sheet assemblyinposition againstthe guide 22 and allows it to drop between the plates 33and 34 upontthe stop plate 36. Thestop plate 36 at this time isinl thedotted line position shown in Fig; 3 and the stop member 44 is inengagement with the bottom of the boss surface 45,"the roller 43beingiyin the depressed portionlof the cam 43a.

As the drum rotates, the roller 43 moves along the-cam 4312 until itreaches the portion of larger diameter. At thispoirrt the roller 43 ismoved outwardly and causes the arm 39 to swing in. a

counterclockwise direction (see Flgafildto thus move the plate 36 outofJthe way and allow the ycopy sheet assembly to drop 'downinto themargin bar trough24.. As the drum continues t'ci rotate, the cam roller58 strikes theic'am 59 and the lever '52 is moved outwardly, causing thearm 49 to turn about its axis, thereby rotating the shaft 20. The shaft20.carries the arms 48 which in turn carry the plate 46. As the shaft 20turns,

the arms 48 will be made to strike the stop pins 62 thus limiting theadvanceof the plate 46 toward the plate 33 to the amount originally seti l as being necessary to give the proper grip on the copy sheets. Theroller 58 will not have reached the high point ofthe cam 59. when thestoppins continue to turn about its pivot .53 against the tension of thespring 51 until the roller 58 does reach the highlpoint of the camwithout-in any way changing the position of the plate 46. After theplate 46 has moved into engagement with the copy sheet assembly, theroller 3| engages the cam 32 to move the margin bar 24 from the fullline position shown in Fig. 3' to the dotted :line position and thegelatin band l5 on the drum advances into engagement with the copy sheetassembly. The platen roller I8 presses the copy sheet assembly againstthe gelatin band on the drum and the assembly is drawn from between theguide plates 46 and 33 as the drum continues -to rotate. The plate 46acts to keep the several sheets of the copy sheet. assembly properlyaligned without exerting enough force on them to impede their advance.

It will be evident from the foregoingdescripkit he suflicient pressureexerted to move the arms 48 against thestopstz.

This apparatus hasthe advantage also that in theinitial laying of. themaster copy on the hectograph pad the plate 46 may be set to bear solightly as to not mar the master sheet that is applied against thehectogra'ph pad. A positive stop-'62 is thus provided for the plate 46,which stop is independent of the connections between the arms=48- andthe cam roller 58 and cam 59. i

In the making of copies the adjustments must be quite close to enableone to feedthemaster copy to the drum without marring its surface,

and to thereafter feed copy sheet assemblies to the drum and hold theminproper relation. The present apparatus has been found to give thenecessary nicetyof adjustment without danger of getting out of order inuse. 4

- While there have been shown and described certain embodiments of theinvention, it is to be understood that it is capable of manymodifications. Changes, therefore, may be made without departing fromthe scope of the invention as described in the appended claims, in whichit is. the intention to claim all novelty inherent in the invention asbroadly as possible, in view of the prior art.

I claim:

1.111 a duplicatingmachine, the combination of a drum rotatably mountedon a horizontal axis and having a recess in its peripheral surface, aplaten roller rotatably mounted in position to press onssaid drum, anobliquely positioned paper uide along which copy sheet assemblies areadapted to move downwardly one at a time toward said platen roller, abar extending across adjacent to the face of said roller,meanscomprising a thin resilient plate movably mounted in position forpressing a copy sheet assembly lightly against said bar and adapted tobe flexed "readily for applying pressure effectively on differentportions of the assemblyof difierent thickness, and adjustable means forlimiting the move- 62 stop thearms 48. However, the lever 52 may .mentof said resilient plate toward said bar for peaking the mechanismeffective with assemblies of different maximum thickness.

2. In aduplicating machine, the combination 0f a. drum rotatablymountedon a horizontal axis and, havinga recess in its peripheral surface, aplaten rollertrotatably mounted in position to press onsaid drum, anobliquely positioned paper j guide along which copy sheet assemblies are:adaptedto move downwardly oneat a time toward'said platen roller, aplate rigidly mounted lin downwardly convergent position with respect tosaid paper guide in front of the guide and cut outintermediately so'asto leave its lower edge portion in the form of a bar positioned closelyadjacent to the" face of the platen roller, a thin resilient platemovably mounted in positionfor pressing acopy sheet assembly lightlyagainst saidbar and adapted to be flexed readily for applying pressureeffectively on differs ent portions of theiassemblyof diiferentthickness, means for .movingjsaid resilient plate toward saidb8;l'.,.1a,n'd;. adjustable means for limitting thesmovement ofsaidresilient plate toward the bar.

said barifor providing a predetermined clearancelbetween the resilientplate and the bar so as to prevent the application of excessivepressureon said resilient plate.

3. In a duplicating machine, the combination of a drum rotatably mountedon a horizontal axis and havingfa recessiinits peripheral surface, aplaten roller rotatably mounted in position to press on said drum, anobliquelypositioned paper guide along which copy sheet assemblies areadapted to move downwardly one at a time toward said platen roller, aplate rigidly mounted in. downwardly convergent position with respect to.said paper guide in front of the guide and cut out intermediately soasflto leave its lower edge portionin theform of a bar positionedclosely adjacent to the face of theplaten roller, a thin resilient platemovably mounted in position for pressing a copy sheet assembly lightlyagainst said bar and adaptedto be flexed readilyfor applying pressureeffectively on different portions of the assembly of differentthickness, adjustable means for limiting the movement of said resilientplate toward said bar for providing a predetermined clearance betweenthe resilient plate and the bar so as to prevent the application ofexcessive pressure on said resilient plate, and means for moving saidresilient platetoward said bar and comprising an actuating memberyieldingly mounted with respect to said resilient plate so as to permitthe actuas to swing in unison, a; thin resilient plate mounted betweensaid arms and extending transversely beyond the arms in position toswing toward and from said bar for pressing a copy sheet assemblylightly against the bar, said plate being bendable transversely andlongitudinally and adapted to be flexed readily so as to apply pressureeffectively on different portions of the assembly of differentthickness, a third arm connected with said first-named arms for movingsaid resilient plate toward and from said bar, a i

fourth arm, pivotally connected with said third arm so as to have alimited swinging movement with respect thereto, means for giving saidfourth arm a swinging movement in the direction for carrying saidresilient plate toward said bar, and yielding means tending to move saidfourth arm to thelimit of its motion with respect to said third arm forcarrying said resilient plate toward said bar but adapted to yield forpermitting the resilient plate to move in the direction away from 5. Ina duplicating machine, the combination of a drum rotatably mounted on ahorizontal axis and having a recess in its peripheral surface, a

platen-roller rotatably mounted in position to press on said drum anobliquely positioned paper guide .along which copy sheet assemblies areadapted toimove downwardly one at a time toward said platen roller, abar extending across 5 adjacent to the face of said roller, arms swingingly mounted at opposite sides of the machine and rigidlyconnectedtogether so as to swing in unison, a thin resilient platemounted between said arms and extending transversely beyond the 'armsinposition to swing toward and from said baryfor pressing a copy sheetassembly lightly against the bar, said plate being bendable transverselyand longitudinally and adapted to be flexed readily so as to applypressure effectively on difierent portions of the assembly of differentthickness, yielding means tending to swing said arms in the directionfor'carrying said resilient plate away from said bar, adjustablestopmeans for limiting the movement of saidarms inboth directions forcontrolling the movement ofsaid resilient plate toward and from saidbar, a third arm connected with said first-named arms jfor movingsaidresilient plate toward and-from said bar, a fourth arm pivotallyconnected with said third arm so as to have a limited swinging movementwith respect thereto, means for giving said fourth arm a swingingmovementin the direction for carrying said resilient plate towardsaidbar, and other yielding means tending to move said fourth arm to thelimit of its motion with respect to said third arm for carrying saidresilient plate toward said bar but adapted to yield for permitting theresilient plate to move in the direction away from the bar independentlyof any swinging movement of said fourth arm.

6. In a duplicating machine, the combination of a drum, a platen rollerrotatably mounted in position to press on said drum, a bar adjacent tosaid platen roller, and means to guide a sheet assembly past said bar tothe drum and platen roller, including a plate movably .mounted to movetoward and away from the bar for pressing sheets lightly against saidbar, and means for moving said plate toward said bar comprising anactuating member and a yielding connection between the actuating memberand the plate providing limited movement of the actuating member in adirection to urge the plate toward the bar without correspondingmovement of the plate toward the bar. I

7. In a duplicating machine, the combination of a drum, a platen roller.rotatably mounted in position to press on said drum, a bar adjacent tosaid platen roller, and means to guide a sheet assembly past said bar tothe drum and platen roller, including a plate movably mounted to movetoward and away from the bar for pressing sheets lightly against saidbar, and means for moving said plate toward said bar comprising anactuating member and a yielding connection between the actuating memberand the plate providing 1, limited movement of the actuating member in adirection to urge the plate toward the bar with-. out correspondingmovement of the plate toward thebar, and adjustable stop means limitingthe approach of the plate to the bar.

8. In a duplicating machine, the combination of a drum, a platen rollerrotatably mounted in position to press on said drum, a bar adjacent tosaid platen roller, and means to guide a sheet assembly past said bar tothe drum and platen roller, including arms swingingly mounted atopposite sides of the machine and rigidly connected together so as toswing in unison, a thin resilient plate mounted between said arms andextending transversely beyond the arms-in posi tion to swing toward andfrom said bar for pressing a copy sheet assembly lightly against thebar, said plate being bendable transversely and,

longitudinally and adapted to be flexed readily so as to applypressureefiectively on difierent portions of the assembly of difierentthickness,

a third arm connected with said first-named arms for moving saidresilient plate toward and from said bar, a fourth arm pivotallyconnected with said third arm 50 as tohave a limited swinging movementwith respect thereto, means for giving said fourth arm a swingingmovement in the direction for carrying said resilient plate to- Wardsaid bar, and yielding means tending to move said fourth arm tothe'limit of its motion with respect to said third arm for carrying saidresilient plate toward said bar but adapted to yield for permittingtheresilient plate tomove in the direction away from the bar.

9. In a duplicating machine, the combination of a drum, a platen rollerrotatably mounted in position to press on said drum, a bar adjacent tosaid platen roller, and means to guide a sheet assembly past said bar tothe drum and platen roller, including a thin resilient plate movablymounted in position forpressing a copy sheet assembly lightly againstsaid bar and adapted to be flexed readily for applyingpressureeffectively on different portions of the assembly of differentthickness, adjustable means for limiting the movement of said resilientplate toward said bar for providing a predetermined clearance betweenthe resilient plate and the bar so as to prevent the application ofexcessive pressure on said resilient plate, and means for moving saidresilient plate toward said bar and comprising an actuating memberyieldingly mountedwith respect to said resilient plate so as to permitthe actuating mem-' her to move without corresponding movement of theresilient plate.

ROBERT ALONZO WILLIAMS.

